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1286 |
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Tuesday, June 03, 2008, Room 04 12:10 PM Corrosion Protection 2 Corrosion protection through thermal sprayed coatings including cathodic and high temperature corrosion, coating of large areas for offshore facilities and comparable applications |
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Structure and corrosion behavior of 316L stainless steel coatings formed by HVAF spraying |
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Zhensu Zeng* / Kurashiki Boring Kiko Co.,Ltd., Okayama Nobuaki Sakoda / Kurashiki Boring Kiko. Co., Ltd., Japan Toshiro Tajiri/ Kurashiki Boring Kiko. Co., Ltd., Japan Seiji Kuroda/ National Institute for Materials Science, Japan |
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SUS316L coatings were sprayed by HVAF system to reduce oxidation for improving the corrosion behavior of stainless coating. The effects of powder feed rate and particle size on the microstructure, oxide amount and adhesion strength of the coatings were investigated. The corrosion resistance of the coatings was evaluated by salt spray test. Oxide amount in the coatings sprayed by HVAF process is below 7% and adhesion strength is not excess of 34MPa. Comparing with HVOF coating, the oxides amount and adhesion strength are much decreased because insufficient soften of particles and insufficient deformation of splats in HVAF coating. With the increase of powder feed rate and particle size, there is a tendency of reduction in oxides, and obvious decease in adhesion strength. The coating deposited is original porous, and it becomes density through the peening effect by the impingement of the following spray particles. Corrosion resistance of the coatings with non sealing-treated is insufficient, and this becomes notable with the increase of powder feed rate and particle size. The sealing-treated coating sprayed with larger size of powder shows good corrosion resistance and it is superior to the coating sprayed by HVOF process. |